Substance use is common among men who have sex with men (MSM) and is a driving force in the MSM HIV epidemic. Substance use just before or during sex substantially increases HIV risk. But few interventions have been tested to address episodes of substance use and sexual HIV risk among MSM. Therefore, in response to the CDC RFA Adopting and demonstrating the adaptation of prevention techniques for persons at highest risk for acquiring or transmitting HIV, we will collaborate with Dr. James Dilley, the Principal Investigator of one of the RFA-required evidence-based interventions (EBIs). We will adapt and rigorously evaluate Dr. Dilley's single-session intervention, Personalized Cognitive Risk-Reduction Counseling, among substance-using MSM (SUMSM), one of the target populations specified by the RFA. In a randomized trial, the original intervention demonstrated robust and sustained reductions in sexual risk among HIV-negative MSM. However, it did not address substance-use related sexual risk reduction, and fewer than 20% of participants reported using the substances we will target. HIV-negative SUMSM who engage in concurrent substance use and sexual risk ("episodic SUMSM") are therefore a new target population in which to adapt this effective sexual risk-reduction intervention. The original EBI takes a cognitive approach to behavior change and is focused on challenging the self-justifications (thoughts, attitudes, and beliefs) used at the time of an unsafe sexual encounter. We will adapt the intervention to address the self-justifications episodic SUMSM employ when engaging in substance use and concurrent high-risk sex. We will focus on use of methamphetamine, powder or crack cocaine, poppers, and binge drinking (> 5 drinks) during sex because these substances are most consistently associated with HIV risk. We will conduct the study in community-based organizations that serve men of color and will enroll an ethnically diverse sample. Our specific aims are: 1. To conduct formative research through individual interviews and pilot testing to adapt the core elements of the EBI, including the core self-justifications elicitation instrument, with a focus on eliciting and intervening on the thoughts, attitudes, and behaviors that episodic SUMSM employ when using substances and engaging in concurrent sexual risk. 2. To determine the efficacy of the adapted intervention in reducing unprotected anal sex, as compared to an attention-control arm, in a randomized trial of 325 episodic SUMSM with 3, 6, and 12-month follow- up. Our primary hypothesis is: Persons randomized to the intervention arm will decrease unprotected anal sex behavior compared with persons in the control arm. 3. We will also: i) Determine the cost-effectiveness of the intervention in reducing sexual risk; ii) Determine the efficacy of the intervention in reducing substance use; iii) Explore whether the intervention reduces incidence of sexually transmitted infections. [unreadable] [unreadable] [unreadable]